棉花膜下滴灌水盐胁迫研究

为探寻干旱半干旱区棉花微咸水膜下滴灌灌溉制度,在南疆地区开展了田间试验,对比分析了水分胁迫及盐分胁迫处理棉花的产量及长势,探讨了膜下滴灌条件下棉花对水盐胁迫的响应。试验采用WDY-500A微电子叶面积测量仪测定叶面积,并进行人工测产,采用原子吸收仪和滴定法测定土壤盐分。结果表明,轮灌处理A(苗期灌淡水)产量最高,为5 427kg/ha,其次是处理C(花铃前期灌淡水),为4 819.5kg/ha;棉花生育期对水分亏缺的敏感性为:花铃前期>蕾期>花铃后期;对盐分胁迫的敏感性为:苗期>蕾期>花铃前期>花铃后期;灌水总量越大,棉花株高越高,叶面积指数也越大;某时段出现水分亏缺,该时段株高和叶面积指数增长幅度减小;越早给棉花灌溉淡水,棉花株高越高,叶面积指数越大;膜下滴灌条件下,淡水灌溉可以有效淋洗棉花根区土壤多余盐分,保证土壤环境安全,但是微咸水灌溉对棉花根区盐分淋洗效果不佳,且对土壤环境有一定的危险性,需在适当时期(如非生长期)采用较大灌水定额洗盐。     

微咸水膜下滴灌灌溉制度试验研究

为了探讨科学合理的微咸水膜下滴灌灌溉制度,在新疆巴音郭楞蒙古自治州水利管理处国家重点灌溉试验站进行了不同灌溉定额、灌水频次的微咸水膜下滴灌大田试验。研究结果表明:①灌溉定额4500m3/hm2、灌水频次10次,灌溉定额3000m3/hm2、灌水频次7次,均有利于保持土壤水分。②当灌溉定额≤4500m3/hm2时,灌溉定额越大,土壤积盐越严重;在灌溉定额一定时,灌溉次数越多,土壤积盐越严重。③当灌溉定额≤4500m3/hm2时,灌溉定额越大,棉花产量越高,微咸水灌溉影响棉花产量的灌溉定额上限在4500m3/hm2左右;灌溉定额多时,灌水次数多棉花产量高,灌溉定额少时,灌水次数少棉花产量高。④灌溉水分生产率随着灌溉定额的增大而减小,在灌溉定额大时,采用少量多次灌溉,在灌溉定额小时,采用多量少次灌溉,均可提高灌溉水分生产率。⑤以节水、控盐和高产为优选标准,当地较为理想的微咸水膜下滴灌模式为灌溉定额3750m3/hm2、灌水次数20次、灌水间隔为7d。     

膜下滴灌棉花根系发育特征及其与土壤水盐分布的关系

为探讨膜下滴灌条件下水分和盐分对棉花根系空间发育的影响,在花铃期选择相同灌溉制度、咸淡水灌溉的两个膜下滴灌处理田块采集距滴灌带不同距离、不同深度上的根系样品144 件。用1 mm 土筛和手拣将棉花根系从土壤中筛分出来,去除死根,冲洗干净后用扫描仪扫描成tif 格式图像,再用DT-SCAN 软件计算根长密度。对比分析发现膜下滴灌及盐胁迫条件下,咸水灌溉的根系分布范围较大,其总根长密度比淡水大31.69 mm/cm3,根系生长深度也远大于淡水灌溉。咸水灌溉根系分布主要受盐分胁迫,淡水灌溉根系分布主要受水分胁迫。水平方向上距滴头40 cm以远,水分胁迫对根系发育起主导作用。土壤体积含水率在20% 以上、电导率在2 000 μs/cm 以下时可以满足根系的正常生长发育。     

NaCl和Zn对棉花生长及营养元素吸收的影响

微咸水在西北干旱区广泛分布, 越来越多地被运用于灌溉棉花(Gossypium hirsutum L.)等作物.微咸水中NaCl和微量元素含量比淡水高, 有关NaCl和微量元素各自对棉花生长的影响已有大量研究, 而他们对棉花生长的相互作用研究比较缺乏.选取对棉花生长作用敏感的NaCl和微量元素Zn, 开展不同NaCl和Zn浓度灌溉水盆栽试验.结果表明, 缺Zn环境下, 在灌溉水电导率为2.90~3.95 dS/m的范围内, 随着电导率增大, NaCl促进棉花根和地上部生长及皮棉产量增加.富Zn环境下, 灌溉水电导率大于5.04 dS/m时, 随着电导率增大皮棉产量明显下降.在灌溉水中Zn浓度为0.192 0~3.068 0 μmol/L的范围内, Zn浓度越大棉花营养生长越快; 大于0.767 6 μmol/L时, 随着Zn浓度增大皮棉产量下降.灌溉水中NaCl和Zn对棉花生长和产量的影响作用, 表现为相互拮抗作用关系.棉花叶的Ca、K、Mg、B和Fe含量以及铃的Cu和Zn含量高于其他组织, Na和Mn不易迁移, 易富集在棉花根部.Zn在盐胁迫条件下影响棉花对营养元素的吸收, 使棉花体内相关营养元素含量发生变化, 进而影响棉花生长及产量.      

典型植棉生态系统内棉田溶质分布与变化的影响因素

正微咸水中微量元素(铜、铁、锰、锌、硼等植物生长必须的元素)含量高于淡水,有利于增加植物对养分元素的吸收,提高水资源利用率(Jin et.al,1998)。但若利用不当,微咸水中高浓度的盐害离子(如Na~+)则会诱发土壤盐渍化,尤其是在干旱、半干旱地区,田间土壤盐分大量累积会造成作物减产。多年来,新疆棉花种植过程中偏施氮肥的现象普遍,磷、钾肥所占比例偏小,基本不施或盲目施用微量元素肥料(韩春丽,2010)。在长期、     

微咸水膜下滴灌对温室乳瓜产量及品质的影响特性研究

本文采用正交试验,研究了防渗技术、微咸水利用方式对温室膜下滴灌乳瓜产量及品质的影响。结果表明,一定矿化度的微咸水灌溉会增加作物土壤根系层含盐量和阻碍作物根系吸水,在灌溉方式和灌水定额一定的情况下,虽然全塑料薄膜防渗保水效果强于四周塑料薄膜+底部粘土防渗,但是四周塑料薄膜+底部粘土防渗透气性好,土壤呼吸作用强,在高温时可以及时调节土壤温度,并有利于乳瓜根部呼吸和生长,使其光合速率升高,有助于乳瓜水分和干物质积累,从而获得增产。     

微咸水膜下滴灌对沙漠温室黄瓜产量的影响研究

膜下滴灌技术在干旱地区得到了广泛的推广。黄瓜是目前种植面积最大的温室蔬菜之一。此外,水分是影响黄瓜生长和品质的重要因素。西北干旱地区淡水资源总量不足,但咸水资源丰富,因此,在我国西北找到适合黄瓜咸水灌溉方案至关重要。在沙漠温室膜下滴灌条件下,采用咸水灌溉黄瓜。本研究揭示了黄瓜产量及黄瓜水盐生产模型。本文研究了黄瓜产量与作物需水量、土壤电导率等生产函数的估算问题。利用田间试验数据估算作物水盐生产函数,为在我国西北干旱地区,特别是宁夏回族自治区推广咸水膜下滴灌技术提供了科学依据。     

干旱区膜下滴灌棉田表层土壤盐分日内动态特征

利用便携式土壤盐分计测量膜下滴灌棉田不同位置和不同深度的土壤电导率,来研究膜下滴灌条件下表层土壤电导率的日内变化特征.结果显示:干旱区一膜两管膜下滴灌条件下,窄行处土壤电导率值最低,膜间最大,宽行居中,表层土壤电导率值存在显著的日内变化特征,早晚土壤电导率值低,中午电导率值高,上午的上升速率大于下午的下降速率;窄行处相对变化幅度大,膜间绝对变化幅度大,土壤电导率值日内变化幅度随深度呈减小趋势;膜下滴灌情况下,表层土壤电导率值的变化受土壤温度和气温的影响显著,但二者相关性复杂,不同深度、不同时间段的相关性不同,膜间大多呈显著正相关,窄行大多呈非显著正相关,宽行处上午呈非显著正相关,但下午呈显著负相关.     

基于染色示踪的膜下滴灌棉田水盐运移规律

采用亮蓝FCF染色示踪剂, 研究膜下滴灌条件的水盐运移规律; 分别在灌溉前、灌溉中和灌溉后等不同时间段共开挖13个时刻的剖面, 观察膜下滴灌湿润面的运移情况; 以10 cm间隔的网格, 用MP406土壤水分探测器原位测定3 120个点的土壤体积含水率, 同时取1 430份土样, 利用1∶5土水比浸提法测定土壤盐分; 并利用WATCHDOG气象站监测研究区气象要素.结果表明: 染色示踪能直观表征土壤水盐运动轨迹; 膜下滴灌条件下, 垂直滴灌带方向土壤水流呈点源入渗特征、沿滴灌带方向近似呈线源入渗特征; 现行灌溉模式下, 壤质砂土湿润锋横向运移速率约为8 cm/h; 滴灌对滴头附近土体有一定洗盐效果, 未覆膜区域地表土体出现盐分积累; 灌水时间越长, 湿润锋越深, 横向扩展速率接近无作物小区(8 cm/h); 从土壤水合理利用角度考虑, 满足研究区一膜一带四行的种植模式和土质的单次合理灌水量应为29.4~69.8 mm.      

典型石漠化区不同种植年限桃树下土壤微量元素变化特征

为明确石漠化地区不同种植年限果树根系表层土壤微量元素的变化特征,选择桂林市恭城县大岭山村同一农户的不同种植年限桃树（2 a、10 a、20 a）各5棵,以撂荒地（0 a）作为对照,对土壤微量元素铁、铜、锰、锌、硼的全量及有效态变化规律进行研究,并探讨理化性质与微量元素有效态的相关性。结果表明:（1）研究区除全铁的变异系数小于10%,铜、锰、锌、硼的全量及有效态均为中等变异;（2）土壤铁、铜、锌、硼全量种植0~2 a间均增加（P<0.05）,种植2~10 a则下降（P<0.05）,种植10~20 a间铁元素随年限增加而下降（P<0.05）,其余研究元素全量均表现为增加趋势;（3）有效铁、锌、硼在种植0~10 a先增加（P<0.05）,种植10~20 a均有明显下降趋势,有效锰在0~20 a间趋势则与其他元素相反,并且与全量锰保持一致性,因此种植10 a是果树土壤微量元素变化的转折点;（4）不同种植年限果树根系土壤性质的改变（pH值、有机质、全磷的变化）是微量元素有效态含量随时间变化的主要内在原因,而人为活动如施加有机肥是外在原因。在种植10 a后,应重视微肥的施加。      

基于氢氧稳定同位素识别干旱区棉花水分利用来源

棉花是我国西北内陆干旱地区主要的农作物,研究干旱区棉花的水分利用来源对合理制定灌溉制度、实现农业节水灌溉和保证作物稳产高产具有重要意义.在新疆生产建设兵团炮台土壤改良试验站,基于水文监测和氢氧稳定同位素方法分析膜下滴灌棉田土壤水中氢氧同位素的动态变化特征,确定棉花不同生育期及灌溉后的水分利用来源,并应用多水源混合模型(IsoSource模型)定量计算了棉花对不同深度土壤水的利用率.研究结果表明:棉花在蕾期、花期、铃期和吐絮期主要的水分利用来源及利用率分别为0~30 cm(78.2%)、30~60 cm(31.9%)、60~110 cm(32%)、110~220 cm(47.3%),整个生育期内水分利用来源存在由浅变深的规律.膜下滴灌后,棉花调整其水分利用来源,显著增加了0~30 cm浅层土壤水的利用率.综合试验结果表明低额高频的灌溉制度可以提高棉花对灌溉水的利用率.      

Effect of treated municipal wastewater on bean growth, soil chemical properties, and chemical fractions of zinc and copper

The current study was carried out in order to investigate the short-term effect of different dilutions of wastewater on soil chemical properties, chemical fractions of zinc (Zn) and copper (Cu), and to assess the chemical buildup of heavy metal on two bean species. The experiment was performed as factorial based on completely randomized design with different dilutions of wastewater on two bean cultivars in two soil textures. The treatments consisted of irrigation with treated wastewater over all growing season, irrigation with wastewater and freshwater in equal proportions, and irrigation with well water only as control. The result showed that soil parameters are significantly affected by application of wastewater irrigation. Irrigation with wastewater increased the concentrations of organic matter, electrical conductivity, N, K, P, Fe, Cu, Zn, Mn, and Ni in soils compared to the control treatment. However, their values were all below international standards. Application of wastewater decreased soil pH and calcium carbonate equivalent. Plant tissue analysis showed increases in N, P, K, Zn, Cu, Zn, and Mn concentrations in grain and frond of beans in wastewater treatment as compared to the control. The concentrations of all elements in plants were lower than the toxic threshold. Chemical fractionations of Zn and Cu indicated that chemical forms of these metals were affected by irrigation with wastewater. Irrigating with wastewater resulted in the movement of Zn from the labile fractions towards the nonlabile fractions. In turn, mobility factor of Cu increased with application of wastewater. Maximum fresh and dry yields of beans were obtained from wastewater treatment compared to the control treatment. This study indicated that wastewater irrigation improves soil properties, plant growth, and yield without any contamination in soil and toxicity in plants.     

冬小麦田咸水灌溉与土壤盐分调控试验

利用浅层咸水灌溉，可使浅层咸水分布区无效降水转化为有效水资源，缓解北方水资源紧缺的矛盾；通过王瞳试验场进行的咸水灌溉与土壤盐分调控试验表明，利用3g/L左右的微咸水连续灌溉5a，根层土壤溶液浓度未超过小麦的耐盐能力，且作物增产；多年盐分变化趋势为：1994－1997年1m深度内土壤总含盐量在一定范围内波动，总体变化不大，连续干旱的1997－1998年略呈上升趋势；麦秸覆盖和施有机肥能减少根层土壤盐分，对土壤盐分具有有利的调控作用，具有增产效果。     

基于正交设计的旱区棉花膜下滴灌最优化探究

以旱区广大群众最为关心的种植密度,滴水量,施肥量为考虑因子,将棉花单铃重,衣分,籽棉产量作为考查指标,把正交试验设计方案引入高密度棉花膜下滴管研究中.采用归一化处理不同数量级的指标,比以往单独考虑各因素对指标的作用,合理而又更加直观;同时考虑了误差对指标的影响,从而提高了F检验的灵敏度.得出了在膜下滴灌的新疆旱区,土壤...     

Sustainable Irrigation with Brackish Groundwater in Heilonggang Region, China

ＢＡＣＫＧＲＯＵＮＤＡＮＤＳＩＧＮＩＦＩＣＡＮＣＥＯＦＳＡＬＩＮＥＷＡＴＥＲＵＴＩＬＩＺＡＴＩＯＮＨｅｉｌｏｎｇｇａｎｇｒｅｇｉｏｎ,ａｓｅｍｉ－ａｒｉｄａｒｅａｗｉｔｈ５００－６００ｍｍａｎｎｕａｌｐｒｅｃｉｐｉｔａｔｉｏｎ,ｌｉｅｓｉｎｔｈｅＥａ...     

Hydrogeochemical investigation of Küçük Menderes River coastal wetland,Selçuk–Izmir,Turkey

Küçük Menderes River forms a rich coastal wetland inside in the Selçuk plain. Three saline/brackish lakes, one swamp and Küçük Menderes River are these wetlands’ components. Alkaline-slightly alkaline type lakes are recharged from precipitation and karstic springs that discharge from marble-schist and marble-alluvium contacts in the northern and southern parts of the study area. Water types of the wetland are Na–Cl and Na–Ca–Mg–HCO₃–Cl in both rainy and dry seasons. Both seawater intrusion and evaporation, as being the sources of the ions, justify the presence of Na–Cl, Na–SO₄ and Cl–SO₄, in the wetland water. Environmental isotopes were used to identify the relationship between wetland and groundwater in the Selçuk plain. The δ¹⁸O and δD composition of wetland area samples have changed between ?6.42 to ?4.56‰, and ?36.40 to ?23.80‰, respectively. The lakes and rivers are plotted on the mixing line by slope of 5.2 and these data indicate that wetland is affected from seawater intrusion. The recharge area that was sampled in order to compare the wetland has Ca–HCO₃ water type with a neutral-slightly alkaline pH values and the main hydrogeochemical process is weathering the different types of silicates. Iron, manganese and selenium are the dominant minor ions due to the high biological activities and organic matters in the lakes. There are two contamination risks for this wetland: (1) waste disposal site and (2) water treatment plant where the purified waters are released into the river. EC, Al, As, Cd, Cu, Fe and Zn values exceed those of aquatic life standards. In the near future these sites will pose a danger for wetland wild life and surrounding irrigation water suppliers.     

Shallow groundwater and soil chemistry response to 3 years of subsurface drip irrigation using coalbed-methane-produced water

Disposal of produced waters, pumped to the surface as part of coalbed methane (CBM) development, is a significant environmental issue in the Wyoming portion of the Powder River Basin, USA. High sodium adsorption ratios (SAR) of the waters could degrade agricultural land, especially if directly applied to the soil surface. One method of disposing of CBM water, while deriving beneficial use, is subsurface drip irrigation (SDI), where acidified CBM waters are applied to alfalfa fields year-round via tubing buried 0.92 m deep. Effects of the method were studied on an alluvial terrace with a relatively shallow depth to water table (～3 m). Excess irrigation water caused the water table to rise, even temporarily reaching the depth of drip tubing. The rise corresponded to increased salinity in some monitoring wells. Three factors appeared to drive increased groundwater salinity: (1) CBM solutes, concentrated by evapotranspiration; (2) gypsum dissolution, apparently enhanced by cation exchange; and (3) dissolution of native Na–Mg–SO₄ salts more soluble than gypsum. Irrigation with high SAR (～24) water has increased soil saturated paste SAR up to 15 near the drip tubing. Importantly though, little change in SAR has occurred at the surface.